3 Find:
a the length of side AB
b the length of the radius of the circle.
4 AB and CM are common tangents to two circles.
Show that:
a M is the midpoint of AB
b AbCB is a right angle.
5 AB is the diameter of a circle with centre O.
AC and BD are any two chords.
If BDOb =®:
a find DBOb
b show that BDOb =ACD.b
6 AB and AC are any two chords which arenotdiameters of a circle with centre O.
X and Y are the midpoints of AB and AC respectively.
Explain why quadrilateral OXAY is a cyclic quadrilateral.
Review set 27B
#endboxedheading
1 Find the value ofx, giving reasons:
abc
de f
A B
C
D
a
O
10 cm 6cm
AB
C
48° x°
O
x°
C
T
A
20°
O
56°
142°
x°
x°
O250°
A M
B
C
x°
79°
x°
562 Circle geometry (Chapter 27)
IGCSE01
cyan magenta yellow black
(^05255075950525507595)
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(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_27\562IGCSE01_27.CDR Monday, 27 October 2008 2:40:59 PM PETER